PURPOSE: To discharge assuredly a content which is overflown from a packaging bag to the outside of the bag and enable to detect a broken bag without overlooking by providing a detector which detects the content which runs out on a vibration conveyor, under the final end of the vibration conveyor.

CONSTITUTION: A detecting device to detect whether a content runs out from a packaged object which is packed in a bag or not, i.e., there is a broken bag or not, is equipped with a vibration conveyor 1 which carries the packaged object ill the right direction while adding a vibration and make the content forcibly run out to the outside of the bag when there is a tear, etc., on the bag itself by the vibration. Under the final end of the vibration conveyor 1, a detector 2 equipped with a receiving tray 4 which receives the content dropping from the final end of the vibration conveyor 1 is provided. This detector 2 is constituted into a shape of Roberval's balance 3 which swings downward by the weight of the content when the receiving tray 4 receives the content, and a limit switch 6 operates by the swing of the balance 3 to detect a defective packaged object.